Originally introduced to the mile-long island of Aoshima to deal with mice that plagued fishermen’s boats, the cats stayed on – and multiplied. More than 120 cats swarm the island with only a handful of humans for company, mostly pensioners who didn’t join the waves of migrants seeking work in the cities after World War Two. Aoshima, a 30-minute ferry ride off the coast of Ehime prefecture, had been home to 900 people in 1945. The only sign of human activity now is the boatload of day-trippers from the mainland, visiting what is locally known as Cat Island.